The present invention relates to a micro-electromechanical system (MEMS) based data storage system, and in particular to MEMS based data storage systems having coarse and fine positioning arrangements.
A MEMS based system can be utilized to generate nanometer-scale motion. Such systems can take advantage of this motion to build the capability of spanning micrometer-scale areas in an x-y plane. An important application of this type of system is in the area of atomic force microscopy (“AFM”) storage applications.
In this application, a polymer medium is used for recording information with a MEMS scanner. Typically, the scanner includes an array of MEMS devices that are able to read, write and erase data on the polymer medium. Each of the MEMS devices includes a micrometer scale tip that can be used to scan the surface of the polymer medium. The tip is heated to a specified temperature and force is applied for writing information in the form of indents and the resistance of the electrical heater is measured to read back the data on the polymer medium. Due to their small size of the tip apex, typically 10 nm, the use of the MEMS scanning devices allows a high data storage density to be achieved.
In general, some form of positioning device is needed to ensure proper alignment of the tip with the medium and to allow a single tip to scan over a broader area. However, due to the level of precision needed and the amount of data output required, the amount of area a single MEMS device could write to is relatively limited. Therefore, to increase the capacity, or scale the amount of data stored with such MEMS based systems requires either the increase in size of the array, or the use of multiple arrays. While each of these techniques has allowed the amount of storage to be increased, it has also increased manufacturing costs as well.
While current data storage systems are suitable for their intended purposes, there exists a need for improvements of high capacity data storage system to allow scalability in the amount of data stored and retrieved with MEMS based devices.